HOW TO: Replace bearings - w/pics

[Don]

The backing pad on my PC recently developed a disturbing 'wobble.' I figured the bearings had worn out.

I looked up on the Porter Cable site and found the parts list as well as a generic instruction on how to disassemble the PC. I really didn't want to have to send my PC out for repair and have to wait even though detailing season is almost over and I surely didn't want to pay labor charges if it was as easy as it seemed. Of course the first step is to remove the backing plate using the flat wrench that should have come with your PC.


In the 2 below pictures, you can see the two torq-bit screws holding the counter weight. Sorry, but I'm not sure of the size. You can see me removing them with a bit from a cordless screwdriver. I prefer to tighten and remove the screws by hand since the PC is made of soft aluminum and it would be very easy to strip out the threads.




In the picture below, you can see the spindle/bearing unit is fully exposed with the removal of the weight. Now you need to reinstall the backing plate.



Below you can see the flat wrench is inserted between the backing plate and the buffer casing. The red arrow shows the flat wrench and the yellow is the spindle. For illustration purposes the green arrow shows how you will use the flat wrench as a lever, although in this picture the weight is still on. Not much pressure is need and the bearing assembly will slide out.





This next picture shows the socket where the bearings and spindle are housed. The screw that is visible is where you would continue disassembly. When I pulled the old bearings out, the sides had a bit of grease on them, so when I replaced the bearings, I smeared some brake caliper grease on the sides of the socket.




In this pic, I'm starting the new bearing assy into place. With the fresh grease on the walls of the socket, the new spindle & bearings popped right in almost effortlessly.



In this final pic, everything is reassembled and you can see that the bearing/spindle is held in place by the counter weight.



I found the bearing/spindle assembly by looking up the authorized repair sites and called a few until I found one that had the assembly in stock. It comes as a unit and cost just under $40.

[DLR Detailing]

Thanks Don for sharing this information with us! You definitely did a fantastic job documenting the repair procedure. This thread will be a very popular one indeed.

Glad you are up and about!!!

Dave

[cwcad]

Originally Posted by DLR Detailing

Thanks Don for sharing this information with us! You definitely did a fantastic job documenting the repair procedure. This thread will be a very popular one indeed.

Glad you are up and about!!!

Dave

I agree most whole heartedly. Thank you for taking the time to give us well needed information.

With your information even a breaker like me could start the fixing plan in motion. Thanks alot!!

[GearHead_1]

Don, Did you by chance see if you could purchase the bearings on this unit from a local vendor? I'm thinking you could and actually press them on the arbor. Is the arbor hexagonal where the bearings rest? I'm thinking probably not. Do you by chance have the old bearing number?

[Don]

Originally Posted by GearHead_1

Don, Did you by chance see if you could purchase the bearings on this unit from a local vendor? I'm thinking you could and actually press them on the arbor. Is the arbor hexagonal where the bearings rest? I'm thinking probably not. Do you by chance have the old bearing number?

I'm sure you could get the bearings individually w/o much trouble, I'll look after work to see if there's a number on the bearing (I'd look now, but with my contacts in, I can't see squat close up). The arbor is round and it's flared over the end which is how the unit is held together on the side opposite the hex piece. The thing is though that the part that is flared over is fairly thin, and when I first tried to tighten the unit up, it developed cracks

[joe.p]

Don,Thank You for the step by step pics this is information that could be used for anyone who needs to replace there bearings on there PC..

[Don]

Originally Posted by GearHead_1

Don, Did you by chance see if you could purchase the bearings on this unit from a local vendor? I'm thinking you could and actually press them on the arbor. Is the arbor hexagonal where the bearings rest? I'm thinking probably not. Do you by chance have the old bearing number?

I looked at the bearings and they have the markings:

TAIWAN NTN 6001L8

If someone knows how to decipher those...

BTW, the easiest way to dissassemble the unit without a proper press is to use a bolt that can be threaded into the unit from the rear (the same size as the backing pad bolt) a piece of 3/4" black pipe (gas pipe) about 2" long and a vise. The hexagonal arbor fits perfectly into the gas pipe and the bolt in the back end is the ram to move the arbor out of the bearings. Very slick and easy.

[BHWilson]

Dear Don,
An excellent job on how to replace bearings. Do you think it will work for a Black & Decker Buffmaster? I have own the same polisher sice 1973 and I do not want to tell you how many times it went back to the factory to have the bearings replaced.

yours truly,
Brian Wilson

[Beemerboy]

I don't have a PC orbital but this is one great write up....also the pics are real good...Thanks

[Poorboy]

Don how often have your berrings gone bad? I've had my pc for about 3+ years and it seems to have no problems (knocking head on wood ..lol )

This should be a sticky thread for those who do encounter this problem

[Don]

Originally Posted by BHWilson

Dear Don,
An excellent job on how to replace bearings. Do you think it will work for a Black & Decker Buffmaster? I have own the same polisher sice 1973 and I do not want to tell you how many times it went back to the factory to have the bearings replaced.

yours truly,
Brian Wilson

I replied to your e-mail, but I didn't realise you had an older machine and not one of the new 'throw aways.' All I can tell you is to start by carefully dissassembling the buffer starting at the backing plate.

[Don]

Originally Posted by Poorboy

Don how often have your berrings gone bad? I've had my pc for about 3+ years and it seems to have no problems (knocking head on wood ..lol )

This should be a sticky thread for those who do encounter this problem

Once (I've owned mine about the same amount of time.) I should also mention my OCD extends to the function of my machines...most people would never even paid attention to the small amount of wobble mine had developed, but it drove me crazy.

[Poorboy]

Originally Posted by Don

Once (I've owned mine about the same amount of time.) I should also mention my OCD extends to the function of my machines...most people would never even paid attention to the small amount of wobble mine had developed, but it drove me crazy.

lol ..I don't think I'd be opening mine up without already having a replacement as I do't know that it would ever run again